Bug: when there is just one paragraphNode, indentation is not exported on copy

[2wheeh]

Lexical version: the latest 0.14.5

Steps To Reproduce

1. make just one paragraphNode with indentation
2. select and paste

Link to code example: can reproduce in the playground

The current behavior

when there is just one paragraphNode, indentation is not applied on exported html. It seems because we can't select only one paragraph with indentations.

https://github.com/facebook/lexical/assets/40269597/c8a68fe3-ad19-4ac5-bcab-33f922d54a4d

The expected behavior

https://github.com/facebook/lexical/assets/40269597/3265c623-453b-41d5-a88e-1bbd51bad365